Functional limit theorems for the maxima of perturbed random walk and divergent perpetuities in the M 1-topology

Springer Science and Business Media LLC - Tập 20 - Trang 567-583 - 2017
Alexander Iksanov1,2, Andrey Pilipenko3, Igor Samoilenko1
1Faculty of Computer Science and Cybernetics, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
2Institute of Mathematics, University of Wrocław, Wrocław, Poland
3Institute of Mathematics, National Academy of Sciences of Ukraine, Kyiv, Ukraine

Tóm tắt

Let (ξ 1, η 1), (ξ 2, η 2),… be a sequence of i.i.d. two-dimensional random vectors. In the earlier article Iksanov and Pilipenko (2014) weak convergence in the J 1-topology on the Skorokhod space of $n^{-1/2}\underset {0\leq k\leq [n\cdot ]}{\max }\,(\xi _{1}+\ldots +\xi _{k}+\eta _{k+1})$ was proved under the assumption that contributions of $\underset {0\leq k\leq n}{\max }\,(\xi _{1}+\ldots +\xi _{k})$ and $\underset {1\leq k\leq n}{\max }\,\eta _{k}$ to the limit are comparable and that n −1/2(ξ 1+… + ξ [n⋅]) is attracted to a Brownian motion. In the present paper, we continue this line of research and investigate a more complicated situation when ξ 1+… + ξ [n⋅], properly normalized without centering, is attracted to a centered stable Lévy process, a process with jumps. As a consequence, weak convergence normally holds in the M 1-topology. We also provide sufficient conditions for the J 1-convergence. For completeness, less interesting situations are discussed when one of the sequences $\underset {0\leq k\leq n}{\max }\,(\xi _{1}+\ldots +\xi _{k})$ and $\underset {1\leq k\leq n}{\max }\,\eta _{k}$ dominates the other. An application of our main results to divergent perpetuities with positive entries is given.

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